Downhole tools have become more complex over time, with increased need to be able to control mechanisms in those tools while they are operational downhole. Conventional downhole controllable tools have used hydraulic techniques that depend on pumps. One problem identified with current downhole technology is that every time the pump is cycled the tool automatically changes its state. This means that an operator running the tool may have to cycle the pump twice or more to get the tool into the required state which may waste rig time and annoy rig personnel.
For example, in a bypass sub embodiment, a rig operator may open the bypass sub on a trip out of the hole but want to be able to pump out of the bypass sub immediately after each connection and not have to provide additional commands to the tool. The bypass sub should just stay open until it is told to close. This has not been possible until now.